Is that even desirable? Sure we really need to get our shit together as a species, but most voted are irrelevant to most people. If I have no stake in an election and no reason to be informed, aside from whatever streamers form my echo chamber, do you really want me voting in something local to you?
Why wouldn’t we still have representatives, organizational structure? If there are some things we all care about like world president, why wouldn’t that organizational structure hold votes like they do now? My state runs an election and gets a result. My country rolls up all the states and gets a result. The world election bureau rolls up all the countries and tabulates the overall. A practical answer doesn’t need the internet and can operate similar to now, except give the UN more power
I think you’re talking about “direct democracy”. Where I live, it’s fairly common to implement that by town hall such that every resident votes for every item. There are good things about that but it’s very unscalable: it only works for small towns. The internet can help with the procedural aspect of scaling, but you’d still be left having to figure out to vote on a massive scale for things you don’t know anything about and have no stake in. Who’s got time for that?